The Qa-1 in mice is homologous to human leukocyte antigen E(HLA-E), and both of them belong to the non-classical major histocompatibility complex I b(MHC-I b) molecules. Qa-1 is capable of presenting self or exogenous antigen peptides to interact with two distinct receptors, namely T cell receptor (TCR) and natural killer cell group 2 member A (or C) (NKG2A/C), thus playing an important role in immune response and regulation. Qa-1-restricted regulatory CD8⁺ T cell (CD8⁺ Treg) is one of the most studied CD8⁺ Treg subgroups, which can maintain immune homeostasis and autoimmune tolerance by exerting immunosuppressive effects. Consequently, Qa-1-restricted CD8⁺Treg cells are closely associated with the occurrence and development of various clinical diseases, such as tumors, infections, autoimmune diseases, and transplant rejections. This paper provides a comprehensive review of the phenotypic characteristics, functional effects, regulatory mechanisms of Qa-1-restricted CD8⁺ Treg cells, as well as the latest research progresses of Qa-1-restricted CD8⁺ Treg cells involved in the pathogenesis of infectious diseases.
Humans ; Animals ; T-Lymphocytes, Regulatory/immunology* ; Histocompatibility Antigens Class I/immunology* ; CD8-Positive T-Lymphocytes/immunology* ; Communicable Diseases/immunology*

OBJECTIVE: To investigate the effect of chidamide on the killing activity of NK (Natural killer cell, NK) cells targeting K562 cells and its related mechanism. METHODS: K562 cells were pretreated with chidamide at different concentrations and cocultured with NK cells at different effect-target ratios. The killing effect of chidamide on K562 cells by NK cells, the expression of natural killer group 2 member D (NKG2D) ligands and apoptosis rate of K562 cells were detected by flow cytometry. RESULTS: The killing sensitivity of NK cells to K562 cells could be enhanced by chidamide. The expression of ULBP2 on K562 cell surface could be up-regulate, however, the expression of ULBP1 and MICA/MICB showed no statistically difference as compared with control group. Chidamide showed no obvious cytotoxicity to K562 cells. CONCLUSION Chidamide can significantly improve killing efficiency of NK cells on K562 cells, which may be related to the up-regulation of ULBP2 expression.
Aminopyridines ; Benzamides ; GPI-Linked Proteins ; Histocompatibility Antigens Class I ; Humans ; Intercellular Signaling Peptides and Proteins ; K562 Cells ; Killer Cells, Natural ; immunology ; NK Cell Lectin-Like Receptor Subfamily K

Animals ; Antibodies, Monoclonal ; pharmacokinetics ; therapeutic use ; Antibodies, Viral ; therapeutic use ; Hepatitis B virus ; immunology ; Histocompatibility Antigens Class I ; metabolism ; Humans ; Macaca fascicularis ; Mice ; Protein Binding ; Protein Engineering ; Receptors, Fc ; metabolism

Human immunodeficiency virus type 1 (HIV-1)-specific cytotoxic T lymphocytes (CTLs) play a critical role in the control of HIV-1 infection and replication. HIV-1 evades CTL mediated pressure through viral escape mutations within targeted CTLs epitopes or flanking regions, but this process is usually associated with a viral fitness cost. The mutated epitopes may weaken the level of the original CTL responses, however, the immune system holds potential to mount denovo responses towards those newly emerged epitopes. This article briefly summarizes recent research progress regarding the competition between HIV-1's escape mutations and host CTL responses.
Animals ; HIV Infections ; genetics ; immunology ; HIV-1 ; genetics ; immunology ; physiology ; Histocompatibility Antigens Class I ; genetics ; immunology ; Humans ; Mutation ; T-Lymphocytes, Cytotoxic ; immunology ; virology

OBJECTIVETo compare the clinical efficacy of HLA- mismatched related donor (MRD) and HLA-matched unrelated donor (MUD) hematopoietic stem cell transplantation (HSCT) for hematopoietic malignancies.

METHODS174 patients with hematopoietic malignancies undergoing allogeneic HSCT (allo-HSCT) (82 from MRD and 92 from MUD) between June 2002 and December 2012 were enrolled in this retrospective study. Hematopoietic engraftment, graft versus host disease (GVHD), relapse, overall survival (OS) and disease-free survival (DFS) were compared between MRD and MUD group.

RESULTSThere was no significant difference between MRD and MUD group in terms of age, gender, disease type and disease status before transplantation (all P>0.05). The incidence of Ⅰ-IV acute GVHD (aGVHD) was 62.2% and 54.3% in MRD and MUD group (P=0.295); the incidence of III-IV aGVHD between the two groups was 15.9% and 9.8% (P=0.229). The incidence of chronic GVHD (cGVHD) was 28.4% and 45.1% in MRD and MUD group (P=0.036), but there was no significant difference in the incidence of extensive cGVHD between the two groups (9.0% vs 12.2%, P=0.525). The mortality of GVHD was 8.5% and 10.9% in MRD and MUD group (P=0.605). The 10-year OS and DFS were (50.1±6.1)% and (48.8±6.1)% in MRD group, compared with (50.5±6.7)% and (46.3±6.2)% in MUD group (P=0.501, P=0.873, respectively). The 10-year cumulative relapse rate was (21.5±5.7)% and (37.6±7.3)% in MRD and MUD group (P=0.194).

CONCLUSIONMRD is equivalent to MUD in efficacy and safety. Without HLA- matched related donors, MRD is superior to MUD because donor source is unlimited and transplantation could be made promptly according to disease status.

Adolescent ; Disease-Free Survival ; Graft vs Host Disease ; Hematologic Neoplasms ; therapy ; Hematopoietic Stem Cell Transplantation ; Histocompatibility Antigens Class I ; immunology ; Humans ; Neoplasm Recurrence, Local ; Retrospective Studies ; Transplantation, Homologous ; Treatment Outcome ; Unrelated Donors

OBJECTIVETo investigate the effects of donor and recipient anti-major histocompatibility complex class I-related chain A (MICA) antibodies on early renal graft function in renal transplant recipients.

METHODSUsing Luminex200 liquid chip technology, we detected anti-MICA antibodies in 26 deceased donors paired with 43 recipients. We divided the 43 pairs into 4 groups according to different donor and recipient anti-MICA antibody positivity statuses and compared the incidence of acute rejection (AR), serum creatinine at 1 week after transplantation, and renal function recovery time between the groups to assess the effect of donor and recipient anti-MICA antibodies on early graft function.

RESULTSFive of the 26 donors were positive for anti-MICA antibodies (19.2%), with the most common antibody being anti-MICA*019 (40%); 11 of the 43 recipients were positive for anti-MICA antibodies (25.6%), among which anti-MICA*018 was most frequently found (14.6%). AR did not occur in the only anti-MICA antibody-positive recipient receiving an anti-MICA antibody-positive donor graft; AR occurred in 2 (33.3%) of the 6 anti-MICA antibody-negative recipients receiving anti-MICA antibody-positive donor graft, in 4 (40%) out of the 10 anti-MICA antibody-positive recipients receiving anti-MICA antibody-negative donor graft, and in 10 (38.4%) of the 26 anti-MICA antibody-negative recipients receiving anti-MICA antibodies-negative donor graft. The incidences of AR were not significantly different between the groups (P>0.05), nor were serum creatinine levels or renal function recovery time at one week after surgery(P>0.05).

CONCLUSIONDonor or recipient anti-MICA antibody positivity does not seem to significantly affect the incidence of AR or renal function recovery early after transplantation to justify the necessity of monitoring donor anti-MICA antibodies. But still, large-sample studies are needed to further investigate the potential impact of donor and recipient anti-MICA antibodies on the outcomes of renal transplantation.

Adult ; Antibodies ; immunology ; Antibody Specificity ; immunology ; Female ; Histocompatibility Antigens Class I ; immunology ; Humans ; Kidney Function Tests ; Kidney Transplantation ; Male ; Middle Aged ; Tissue Donors

Serum levels of soluble MHC class I-related chain A (sMICA) are related with the prognosis of various types of cancer; however, few studies on the prognostic value of sMICA in hepatocellular carcinoma (HCC) have been reported. In this study, we retrospectively investigated the relationship between sMICA levels and clinical features of advanced HCC, and we assessed the prognostic value of sMICA in advanced HCC. Furthermore, the relationship of serum sMICA levels and natural killer group 2, member D (NKG2D) expression on natural killer (NK) cells was also evaluated. We detected sMICA levels in the serum of 60 advanced HCC patients using enzyme-linked immunosorbent assay (ELISA) and measured expression levels of NKG2D on NK cells using flow cytometry. We found that serum sMICA levels in HCC patients were in the range of 0.10-6.21 ng/mL. Chi-square analyses showed that sMICA level was significantly related with only tumor size. Survival analysis showed that a high sMICA level was significantly related with poor prognosis among HCC patients. Multivariate analyses indicated that sMICA was an independent prognostic factor. In addition, the levels of CD56+NKG2D+ NK cells were within the range of 11.2%-55.4%, and correlation analyses indicated that sMICA level was negatively correlated with the level of NKG2D+ NK cells. Our results suggest that serum sMICA levels may be an independent prognostic factor for advanced HCC.
Adult ; Carcinoma, Hepatocellular ; blood ; immunology ; pathology ; Female ; Histocompatibility Antigens Class I ; blood ; Humans ; Killer Cells, Natural ; immunology ; metabolism ; Liver Neoplasms ; blood ; immunology ; pathology ; Male ; Middle Aged ; Multivariate Analysis ; NK Cell Lectin-Like Receptor Subfamily K ; metabolism ; Neoplasm Staging ; Retrospective Studies ; Survival Rate ; Tumor Burden

Carcinoma, Hepatocellular ; immunology ; Female ; Histocompatibility Antigens Class I ; blood ; Humans ; Killer Cells, Natural ; immunology ; Liver Neoplasms ; immunology ; Male ; NK Cell Lectin-Like Receptor Subfamily K ; metabolism

BACKGROUNDHumoral immunity is an important factor for long-term survival of renal allograft. Here we performed a four-year follow-up to explore the clinical significance of monitoring anti-human leukocyte antigens (HLA) and anti-major histocompatibility complex class I-related chain A (MICA) antibody expression after kidney transplantation.

METHODSWe obtained serial serum samples from 84 kidney transplant patients over a four-year period. All patients were followed up at least 6 months after transplantation and had at least two follow-up points. Anti-HLA and anti-MICA antibody titres and serum creatinine (SCr) levels were evaluated at each follow-up. Patients were divided into 4 groups: HLA(+) MICA(-), HLA(-)MICA(+), HLA(+)MICA(+) and HLA(-)MICA(-). The impact of post-transplant antibody level on kidney allograft function was evaluated.

RESULTSAntibodies were detected in 38.1% (32/84) of the renal allograft recipients. HLA, MICA and HLA+MICA expression was observed in 18.89%, 14.44% and 5.93% of the recipients respectively. The most frequent anti-HLA and anti-MICA specific antibodies identified were A11, A24, A29, A32, A33, A80; B7, B13, B37; DR17, DR12, DR18, DR52, DR53, DR1, DR4, DR9, DR51; DQ7, DQ4, DQ8, DQ2, DQ9, DQ5, DQ6 and MICA02, MICA18, MICA19, MICA07, MICA27. As the time after transplantation elapsed, more recipients developed de novo antibody expression. Total 11.91% (10/84) of the recipients had de novo antibody expression during the follow up. The average level of SCr and the percentage of recipients with abnormal allograft function were significantly higher in recipients with anti-HLA and/or anti-MICA antibody expression than those without. The appearance of anti-HLA and anti-MICA antibody expression always preceded the increase in SCr value.

CONCLUSIONSAnti-HLA and anti-MICA antibody expression has predictive value for early and late allograft dysfunction. The presence of donor specific antibody is detrimental to graft function and graft survival.

Female ; Follow-Up Studies ; Graft Survival ; HLA Antigens ; immunology ; Histocompatibility Antigens Class I ; immunology ; Humans ; Isoantibodies ; analysis ; Kidney Transplantation ; Male ; Minor Histocompatibility Antigens

OBJECTIVETo evaluate the association of major histocompatibility complex class I chain related gene A (MICA) antibodies with acute rejection (AR), chronic rejection (CR) and renal function after renal transplantation.

METHODSSerum MICA antibodies were detected with ELISA before and after transplantation with also examinations of panel reactive antibodies (PRA), serum creatinine, urine, graft ultrasound, lymphocyte subsets and the pathology of graft biopsy. The study was carried out in two parts to monitor MICA antibodies in acute and chronic rejections after renal transplantation.

RESULTSIn the first part of the study 18 of the 41 recipients experienced episodes of acute rejection, and the incidence rate was markedly higher in MICA(+) group than in MICA(-) group (P<0.05). Compared with the recipients with stable renal functions, the patients with acute graft rejection showed a significantly higher positivity rate of MICA antibodies. Postoperative MICA antibody monitoring showed that MICA antibody level increased gradually 2-3 days after the occurrence of acute rejection; anti-rejection treatment lowered serum creatinine to a normal level but MICA antibodies remained positive. In the second part, 21 of 40 patients had chronic graft rejection and showed significantly higher positivity rate of MICA than the patients with stable renal functions (P<0.05). In patients with chronic rejections, the serum creatinine levels were significantly higher in MICA(+) than in MICA(-) cases (P<0.05). Graft biopsy of all MICA(+) cases showed C4d deposition.

CONCLUSIONThe status of MICA antibodies can predict the occurrence and treatment outcomes of acute rejection, and also as one of the major causes of chronic graft rejection, they affect the long-term survival of the renal grafts.

Adolescent ; Adult ; Antibodies ; blood ; immunology ; Complement C4b ; metabolism ; Creatinine ; blood ; Follow-Up Studies ; Graft Rejection ; blood ; immunology ; pathology ; HLA Antigens ; immunology ; Histocompatibility Antigens Class I ; immunology ; Humans ; Kidney ; metabolism ; physiopathology ; Kidney Transplantation ; Peptide Fragments ; metabolism ; Young Adult